West-MEC District Practice Exam 2026 – Comprehensive All-in-One Study Guide for Exam Success!

Peak expiratory flow rate is the maximum speed of air you can blow out in one forced exhale after a full inhalation. This measure is also called peak expiratory flow (PEF) or PEFR, and the terms are used interchangeably in many devices and charts. It’s typically read with a peak flow meter and reported in liters per minute, making it a simple, quick way to monitor how open or narrowed the airways are, such as in asthma management.

This differs from FEV1, which is the amount of air you forcefully exhale in the first second and reflects both rate and volume during a longer expiratory effort. It also isn’t the total lung content measured by TLC, nor the total volume expelled during a full forced exhalation, which is FVC.